IOS开发常用代码汇总2

11.根据文件名，返回UIImage对象

+ (UIImage*)getLocalImageByName:(NSString*)picName

{

NSString *path      = [[NSBundle mainBundle] pathForResource:picName ofType:nil];

    // return [UIImage imageWithContentsOfFile:path];

UIImage *tempImage = [UIImage imageWithContentsOfFile:path];

if (tempImage == nil) {

tempImage = [[UIImage alloc] init];

}

return tempImage;

    

}

12.创建一个带有事件的UIButton

    //创建“发送”按钮

    UILabel *nameLabel;

    UIButton *sendBtn = [UIButton buttonWithType:UIButtonTypeCustom];

    [sendBtn setFrame:CGRectMake(260, 7, 50, 30)];

[sendBtn setImage:[11 getLocalImageByName:@"send_bt.png"] forState:UIControlStateNormal];

[sendBtn setImage:[11 getLocalImageByName:@"send_end.png"] forState:UIControlStateHighlighted];

    [sendBtn addTarget:self action:@selector(sendFeedback) forControlEvents:UIControlEventTouchUpInside];

    [self.view addSubview:sendBtn];

13.根据RGB和Alpha返回UIColor

• (UIColor *) colorFromHexRGB:(NSString *)inColorString inAlpha:(CGFloat)AlphaValue

{

    UIColor *result = nil;

unsigned int colorCode = 0;

unsigned char redByte, greenByte, blueByte;

if (nil != inColorString)

{

NSScanner *scanner = [NSScanner scannerWithString:inColorString];

(void) [scanner scanHexInt:&colorCode]; // ignore error

}

redByte = (unsigned char) (colorCode >> 16);

greenByte = (unsigned char) (colorCode >> 8);

blueByte = (unsigned char) (colorCode); // masks off high bits

result = [UIColor

              colorWithRed:(float)redByte/ 0xff

              green: (float)greenByte/ 0xff

              blue: (float)blueByte / 0xff

              alpha:AlphaValue];

//0xff

return result;

}

14.设置圆角UITextView，显示键盘

    [self.contantTextView becomeFirstResponder];

    self.contantTextView.delegate=self;

self.contantTextView.layer.cornerRadius = 6;

self.contantTextView.layer.masksToBounds = YES;

15.键盘隐藏

    [self.contantTextView  resignFirstResponder];

16. 通常使用Documents目录进行数据持久化的保存，而这个Documents目录可以通过下面方法获得

     NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);

    NSString *documentsDirectory = [paths objectAtIndex:0];

17.弹出视图和消失视图

        弹出：

        FeedbackViewController *ctller = [[FeedbackViewController alloc]init];

         ctller.modalTransitionStyle = UIModalTransitionStyleCrossDissolve;

        [self presentModalViewController:ctller animated:YES];

        消失：

        [self dismissModalViewControllerAnimated:YES];

18.navigationController视图切换和返回

     切换：

    LoginViewController *ctller = [[LoginViewController alloc]init];

[self.navigationController pushViewController:ctller animated:YES];

[ctller release];

     返回：

          [self.navigationController popToRootViewControllerAnimated:YES];

19.新建一个弹出框

              UIAlertView *alert = [[UIAlertView alloc]

                                  initWithTitle:@"提示"

                                  message:@"这是一个测试"

                                  delegate:self cancelButtonTitle:@"确定" otherButtonTitles:nil];

            [alert show];

            [alert release];

20.新建一个多选项的弹出框

        UIAlertView *alert = [[UIAlertView alloc]

                          initWithTitle:@"提示"

                          message:@"这也是一个测试"

                          delegate:self cancelButtonTitle:@"确认" otherButtonTitles:@"取消",nil];

    [alert setTag:2];

    [alert show];

    [alert release];